Guide: NiMH vs Alkaline

NiMH and alkaline AA and AAA cells differ first in rechargeability. NiMH BK cells are rechargeable 1.2 V cells, with capacities given as rated and typical pairs on the BK series page. Alkaline LR cells are primary 1.5 V cells, with sizes and masses given on the alkaline page. Both sets of figures are Panasonic catalog data with brand attribution.

Sizes overlap: both families cover AA and AAA forms, so size alone does not settle a choice. The questions that separate them are rechargeability, the capacity basis, and the intended use. The NiMH capacity basis per the catalog page is 0.2 It discharge after 0.1 It charge for 16 hours; read that basis together with any BK figure.

One BK model's capacities are held back on the series page because the archived columns read in an inverted order. That model is published by name only, and no capacity for it should be read off this guide either.

For an AA or AAA choice, name the model and the family, ask for its datasheet, and confirm the exact model, the capacity, the size, and the ordering steps. Do not choose a cell from a family summary alone.